Field of the Invention
The present disclosure relates to at least one embodiment of an image processing technique for outputting printed materials having brightness that changes when viewed from different angles.
Description of the Related Art
Some textiles, such as satin or embroidered textiles, and hairline-finish metal surfaces, for example, are anisotropic, that is, look significantly different when viewed from different angles due to the complex fine form of the surface thereof. Examples of printed materials that reproduce such anisotropy include printed materials created by using a lenticular lens. Japanese Patent No. 3555420 discloses a technique in which an ultraviolet (UV)-curing inkjet printer capable of forming projections and indentations with an ink that includes a photo-curable resin is used to allow an image and a lenticular lens that is overlaid on the image to be simultaneously formed.
However, in the method as described in Japanese Patent No. 3555420 in which a lenticular lens is used, an image needs to be printed at a high resolution in order to make the brightness and color smoothly change when the angle of view is changed. Further, it is difficult to precisely form a curved surface of the lens at a high resolution by using an inkjet printer.